WO2013186185A1

WO2013186185A1 - Method for producing plastic compound molded bodies

Info

Publication number: WO2013186185A1
Application number: PCT/EP2013/061951
Authority: WO
Inventors: Oliver FRANSSEN; Clemens Trumm
Original assignee: Momentive Performance Materials Gmbh
Priority date: 2012-06-11
Filing date: 2013-06-11
Publication date: 2013-12-19
Also published as: EP2858803B1; EP2858803A1; US20150298375A1; CN104640681B; CA2875458A1; CN104640681A; HK1210740A1; US10384382B2; JP2015523926A

Abstract

The invention relates to a method for producing plastic compound molded bodies, in which hard-soft-molded bodies made of low-melting thermoplastic materials and light-curable polyorganosilozan compositions are produced, and to articles produced according to said method.

Description

- -

METHOD FOR PRODUCING PLASTIC COMPOSITE MOLDING BODIES

The invention relates to processes for the production of composite plastic molded articles in which, in particular, hard-soft molded parts are produced from preferably low-melting thermoplastic or thermosetting plastics and photocurable polyorganosiloxane compositions in a cohesive shaping step.

Composite moldings made of thermoplastics and elastomers such as baby-suckers or keyboards with elastomeric safety mats are known. The sole use of thermoplastics for the production of such moldings is generally not possible, since these have a too high hardness especially for sealing purposes are not rubbery. Also, the feel of the thermoplastic or thermosetting plastics often leaves something to be desired. On the other hand, the softer elastomer components often have inadequate mechanical strength to impart the necessary stability to the molded article. Therefore, there is often a desire to produce Kunststoffverbund- molding, which consist of a hard thermoplastic or thermosetting mold-supporting part and a soft elastomeric often located on the surface part, which in particular determine the feel, electrical properties or the sealing force. Such composite moldings are produced today by mechanical joining of thermoplastic and elastomer parts. A special variant is the two-component injection molding of thermally curable elastomers with thermoplastic parts in a common mold. This crosslinks the elastomers at a temperature above 120 ° C. Previously, the thermoplastic molding must be cooled down from the molten state to solidify or to maintain the mold. This procedure is energetically of course very unfavorable, since first must be heated (shaping of the thermoplastic or thermosetting plastic), then cooled, and then has to be reheated in the cross-linking of the elastomer. In addition, the crosslinking temperature of the elastomer must again not exceed the softening temperature of the thermoplastic. Therefore, only certain particularly high-quality plastics with high heat resistance can be used. The present invention was therefore based inter alia on the problem to produce composite molded bodies also from low-melting, often cheaper plastics with low heat resistance, and thus expand the range of available hard Komposrtmaterialen. In addition, it should also be possible in this way, for example, ecologically compatible alternative materials in the production of such composite form body to use, which is particularly relevant in those areas in which the composite molded article either directly or indirectly comes in contact with people, such as for example, in food packaging. Finally, the energetically unfavorable procedure with two heating steps in the production of composite form body should be avoided.

The inventors found that such composite moldings can be produced in an advantageous manner in which light-curable silicone compositions are used at low temperatures, in particular from 0 to 50 ° C.

With this combination of materials, it is also possible to combine composite parts of any thermoplastics and silicone elastomers by means of molds or molds with thermoplastic inserts as well as with two-component molds, and produce a large number of useful composite moldings economically and ecologically compatible. Furthermore, many of the low-melting thermoplastic resins were now accessible for the production of composite form bodies in the field of food containers, of drinking water supply installations by the present invention for the first time by the inventive method.

With the specific embodiment in which the light-curing silicone composition is irradiated by the plastic molding itself, in particular transparent shapes or forms with transparent components are dispensed with, resulting in a cost reduction of the process, since the usual transparent elements as an integral part of molds for light-curing materials be subject to unwanted aging processes by UV irradiation. The present invention thus relates to a process for the production of composite plastic molded articles, which comprises the steps:

a) providing a molded part of thermoplastic or duromeric resin in a mold,

b) introducing a light-curing silicone composition into said - -

Mold containing said molding,

c) irradiating the light-curing silicone composition with light of the

Curing the silicone composition of appropriate wavelength to form a composite molding of said molding and the cured one

Silicone composition.

In the case of the thermoplastics used in the context of the present invention, these are selected, in particular, from the group of polymers which have a heat distortion resistance (HDT) according to DIN EN ISO 75-1, -2 (preferably according to method B, 0.45 MPa ) of less than 160 ° C, preferably less than 150 ° C, preferably less than 140 ° C, preferably less than 130 ° C and more preferably less than 120 ° C.

Examples of thermoplastics are selected in particular from the group consisting of ABS (acrylonitrile-butadiene-styrene copolymer), polyamides (PA), polyoxymethylene (POM), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyolefins selected from Polyethylene (PE), polypropylene (PP) and polyethylene-dicyclopentadiene polymers (COC), polymethyl methacrylate (PMMA), polyesters, polycarbonates (PC), polyvinyl chloride (PVC), polylactides (PLA), polystyrene (PS), celluloid, thermoplastic elastomers selected from ethylene-propylene-diene rubber or styrene-butadiene-styrene-block copolymer (SBS) and styrene-ethene-butene-styrene (SEBS), and polyurethanes. Particularly preferred are thermoplastic resins, polyolefins such as polyethylene, polypropylene; polystyrene; SECTION. Examples of thermosetting plastics include crosslinked epoxies, bakelites, crosslinked polyester resins, and crosslinked polyurethanes.

The light-curing silicone composition is preferably those selected from the group of hydrosilylation-curing silicone compositions. Particularly preferred are silicone compositions which have the following constituents, preferably, these consist of:

a) at least one polyorganosiloxane having on average at least two unsaturated organic groups per molecule,

b) at least one polyorganosiloxane having on average at least two SiH groups per molecule,

c) optionally one or more fillers, -. d) at least one photoactivatable catalyst comprising a metal selected from the group consisting of Pt, Ru, Rh, Pd, Ir or Ni or a compound of said metal, and

e) optionally one or more auxiliaries.

Component a) (Si-alkene vi)

In the light-activatable, curable siloxane compositions used according to the invention, the alkenyl-group-containing polyorganosiloxane (a) preferably has a viscosity range of 0.025 and 500 Pa.s, preferably 0.1 to 100 Pa.s (25 ° C., shear rate gradient D of 1 s ^). It may consist of a uniform polymer or mixtures of different polyorganosiloxanes, such as various substantially linear alkenyl-containing polymers (a1) or mixtures of the substantially linear polymers (a1) and preferably branched polymers (a2) with relatively high alkenyl content. Content, as described in more detail below, consist.

The polyorganosiloxane (a) preferably consists at least of the siloxane units which are selected from the group consisting of the units M =

and the divalent units R ² , wherein R, R ¹ and R ^{2 are} as defined below.

The alkenyl group content is about 0.017-160 mol .-% based on siloxy groups or 0.002 to about 22 mmol / g for polymethylvinylsiloxanes. These may include both linear and branched polyorganosiloxanes. Preferably, the alkenyl group content at about 0.002 to about 3.0 mmol / g for polymethylvinylsiloxanes is more preferably between 0.004 to 1.5 mmol / g. Preferably, the polyorganosiloxanes (a) are substantially linear, i. the proportion of T and Q units is less than 0.1 mol .-%.

The polyorganosilioxanes (a) can be described by the general formula (I): alDbiT _c1 Q _d iR ² _e1 ] _m1 (!)

wherein

D = F. ^° ^: i 0 _{_2/2,}

T = R ¹ Si0 _{_3/2,} - -

Q = Si0 _{_4/2,}

With

m1 = 1-1000

a1 = 1-10

b1 = 0-3000

d = 0-50

d1 = 0 - 1

e1 = 0-300,

wherein

R = an organic group, preferably unsubstituted and substituted hydrocarbon radicals, more preferably n-C ₁₂ -alkyl, iso-C ₃ -C ₂ alkyl, tert-C4-C _'2 alkyl or Ci-Ci2-AIkoxy- (CrCi ₂ ) alkyl, C ₅ -C _3C rCycIoaIky! or Ce-C ₃₀ -aryl, C 1 -C ₁₂ -alkyl- (C ₆ -

C o) -aryl, where these radicals R may be optionally substituted by one or more F atoms and / or may contain one or more -O-groups.

Examples of suitable monovalent hydrocarbon radicals R include alkyl groups, preferably CH ₃ , CH ₃ CH ₂ , (CH ₃ ) ₂ CH, CeH-u and C ₁₀ H 2 groups, cycloaliphatic groups, such as cyclohexylethyl, aryl groups such as phenyl, tolyl, xylyl,

Aralkyl groups such as benzyl and 2-phenylethyl groups. Preferred monovalent halogenated hydrocarbon radicals R in particular have the formula C _n F 2n ₊ Me ₂ CH 2 where n has a value of 1 to 10, such as CF ₃ CH ₂ CH ₂ -, C ₄ F ₉ CH ₂ CH ₂ - and

CeFi ₃ CH ₂ CH ₂ -. A preferred radical is the 3,3,3-trifluoropropyl group.

Particularly preferred radicals R include methyl, phenyl and 3,3,3-trifluoropropyl.

R ¹ = R or an unsubstituted or substituted C ₂ -C ₂ alkenyl radical, with

Provided that at least two radicals R ¹ are an alkenyl-containing organic group _"are preferably selected from: unsubstituted and substituted alkenyl-containing hydrocarbon radicals, such as n-, iso- tert-, or cyclic C2-C12 alkenyl, vinyl, allyl, hexenyl, Ce-Cao-cycloalkenyl, cycloalkenylalkyl, norbornenyl-ethyl, limonenyl, Ce-Cao-AIkenylaryl, wherein optionally one or more -O-atoms may be present (corresponding to ether residues) and which may be substituted by one or more F atoms. Preferred radicals R ¹ are groups such as vinyl, allyl, 5-hexenyl, cyclohexenylethyl,

Limonenyi »norbornenylethyl, ethylidene norbornyl and styryl, particularly preferred is vinyl.

R ² = is a divalent aliphatic n-, iso-, tert- or cyclic C _r Ci4-alkylene radical, or a Ce-C ^ -arylene or Alkylenarylrest bridged in each case two siloxy units M, D or T, for example - DR ² -D-. In this case, R ^{2 is} preferably selected from divalent aliphatic or aromatic n-, iso-, tert- or cyclic CI-C - alkylene, Ce-cit-arylene or -Alkylenarylgruppen.

Examples of suitable divalent hydrocarbon groups R ² which can bridge siloxy units include all alkylene and dialkylarylene radicals, preferably those such as -CH ₂ -, -CH ₂ CH ₂ -, -CH ₂ (CH ₃ ) CH-, - {CH ₂ ) c, -CH ₂ CH {CH ₃ ) CH ₂ -,

- (CH ₂ ) 6-, - (CH ₂ ) 8- and - (CH ₂ ) i-cycloalkylene groups such as cyclohexylene, arylene groups such as phenylene, xylene. Their proportion generally does not exceed 30 mol% of all siloxy units. Preferred are groups such as alpha.omega-ethylene, alpha.omega-hexylene or alpha.omega-phenylene.

The indices represent average degrees of polymerization. The indices are preferably as follows and are expediently selected in accordance with the desired viscosity.

The abovementioned polyorganosiloxanes (a) preferably have a structure of the general formula (Ia), preferably of the formula (Ia '),

R ¹ R ₂ SiO (R RSiO) biSiR ₂ R ¹ (Ia),

R ¹ R ₂ SiO (R ₂ SiO) _b iSiR ₂ R ¹ (la ') where R and R ^{1 are} as defined above and b1 <10000.

Preferred siloxy units in the polyorganosiloxanes (a) are, for example, alkenylsiloxy units, such as dimethylvinylsiloxy, alkylsiloxy units, such as trimethylsiloxy, dimethylsiloxy and methylsiloxy units, arylsiloxy units, such as phenylsiloxy units, such as triphenylsiloxy-dimethylphenylsiloxy, diphenylsiloxy, phenyl methylvinylsiloxy, phenylmethylsiloxy units. - -

Preferably, the polyorganosiloxane (a) has a number of siloxy units of from 20 to 10,000, preferably from 100 to 6000, more preferably from 150 to 3000, particularly preferably from 200 to 1500 (average degree of polymerization P _n ).

- -

Component b) (Si-H-containing Polysiloxanes)

The polyorganohydrogensiloxanes (b) are preferably selected from linear, cyclic or branched SiH-containing polyorganosiloxanes of the general formula (II):

wherein

M = R ³ R ₂ S! Oi / _2>

D = ³ RSi0 ₂ / _2l

T = ³ Si0 _3/2 ,

Q = S1O4 / 2, in which

R = n--C ₂ alkyl, iso-C ₃ -C ₁₂ -Alkyi, tert-C4-Ci ₂ alkyl, or C ₁₂ alkoxy (C ₂ Ci) - alkyl, C ₅ -C ₃ o- cycloalkyl or C ₆ -C ₃ o-Aryi, C ₂ -C -Alkyi- (C ₆ -C ₀₎ aryl, where these radicals R, if appropriate, in each case by one or more F atoms can be substituted and / or one or more Contain -O-groups,

R ³ = R or hydrogen, with the proviso that at least two R ^{3 groups} per molecule are hydrogen, both of which may occur simultaneously in one molecule, but at least two R ^{3 groups} per molecule are hydrogen, R is defined above, is preferred R = methyl.

R ² = a divalent aliphatic n-, iso-, tert- or cyclic dC- alkylene radical, or a C _e -C ₄ -arylene or alkylenearyl radical which bridges in each case two siloxy units, D or T,

m3 = 1 to 1000

a4 = 1 to 10

b4 = 0 to 1000

c4 = 0 to 50

d4 = 0 to 1

e2 = 0 to 300.

Polyorganohydrogensiloxanes (b) are preferably linear _"cyciische or branched polyorganosiloxanes whose siloxy units are advantageously selected - -

Q = SiO 4/2, in which these units are preferably selected from MeHSiO- or Me ₂ HSiOo _, 5-units besides optionally other organosiloxy units, preferably dimethylsiloxy units.

The siloxy units can be present in blocks or randomly linked to one another in the polymer chain. Each siloxane unit of the polysiloxane chain may carry identical or different radicals.

The preferred polyorganohydrogensiloxanes (b) are structures derived from the

Group can be selected, which can be described by the formulas (IIIa-llle)

HR ₂ SiO (R ₂ SiO) _z (RHSiO) p SiR ₂ H (purple)

HMe ₂ SiO (Me ₂ SiO) _z (MeHSiO) p Si e ₂ H (IIIb)

Me ₃ SiO (Me ₂ S! O) _z (MeHSiO) p SiMe ₃ (IIIc)

Me ₃ SiO (MeHSiO) _p SiMe ₃ (IIId)

{[R ₂ R ³ Si0 _1/2] ₀ -3 [R ³ Si0 _{_3/2]} ^{[0: 4)} _n2} _m3 (Hie)

{[Si04 / 2}] [R ⁴ Oi / 2] _n2 [R2R ³ SIOI / 2] _0, OMO [R ³ Si0 _3/2] o ~ o ₅ [RR ³ Si0 _2/2] ooo o} _m3 (Ulf) with

z = 0 to 1000

p = 0 to 100

z + p = b4 = 1 to 1000

n2 = 0.001 to 4

wherein R ⁴ 0i / ₂ is an alkoxy radical on silicon,

R ^{3 is} as defined above.

The SiH concentration of the polyorganohydrogensiloxanes (b) is preferably in the range of 0.1 to 98 mole percent, preferably 0.5-95 mole percent, each based on the number of siloxy groups.

Examples of preferred structures of component (b1) in the silicone rubber composition of the invention include chain extenders (b1) such as:

HMe ₂ SiO- (Me ₂ SiO) _z SiMe ₂ H and

MesSiO-iMe ^ iO MeHSiO ^ SiMeg, - -

[(Me ₂ SiO) _z (MeHSiO) ₂ ]

Me ₃ SiO- (eHSiO) _p SiMe ₃ ,

HMe ₂ SiO (Me ₂ SiO ePhSiO) _z (MeHSiO) _p SiMe 2 H,

(MeHSiO) p,

(HMe ₂ SiO) ₄ Si

MeSi (OSiMe ₂ H) ₃

wherein p, z are as defined above.

The SiH content is determined in the present invention by ¹ H-NMR see AL Smith (Ed.): The Analytical Chemistry of Silicones, J. Wiley & Sons 1991 Vol. 12 p. 356 et seq. In Chemical Analysis ed. By JD Winefordner.

The preferred amount of the polyorganohydrogensiloxanes (b) is 0.1 to 200 parts by weight based on 100 parts by weight of component (a).

The ratio of SiH to Si alkenyl units can affect many properties, such as rubber properties, crosslinking speed, stability, and surface tack. Component c) (filler)

The silicone rubber mixtures used according to the invention optionally further comprise one or more optionally superficially modified fillers (c). Superficially modified fillers are fillers which are hydrophobized before or during dispersion in the polymer (compounding process) with silanes, silazanes or siloxanes. Organofunctional groups which participate in the crosslinking reaction, ie preferably unsaturated groups such as vinyl groups, may also be present. In addition, preferred silanes, silazanes or siloxanes have HO, -NHR, RO groups on the Si atom which can react with water or with the silica. The fillers include, for example, all finely particulate, in particular oxidic fillers, ie, the particles have less than 100 pm (exclusion limit). These may be mineral fillers such as silicates, carbonates, nitrides, oxides, carbon blacks or silicas. Preferably, the fillers are so-called reinforcing silicas which allow the production of opaque, more transparent elastomers, - ie those which improve the rubber mechanical properties after crosslinking, increase the strength, such as pyrogenic or precipitated silica with BET surface areas between 50 and 400 m ² / g, which are here preferably hydrophobic in a special way superficially. The component (c), when it is inserted _"in amounts of 1 to 100 parts by weight, preferably 10 to 80 parts by weight teiien, more preferably 20 to 60 parts by weight, based on 100 parts by weight of component (a) used ,

In a preferred embodiment, the silicone composition used according to the invention comprises at least one reinforcing filler (c), in particular fumed silica, having a BET surface area of more than 50 m ² / g, preferably more than 80 m ² / g. The light-curing silicone compositions used according to the invention preferably have at least one of the abovementioned oxidic fillers, in particular silica with the mentioned BET surface areas. The choice of fillers is such that a sufficiently fast and complete light curing is possible. Surprisingly, the addition of the mentioned oxidic fillers down to transmissions (light transmission at 400 nm wavelength and a thickness of the test specimen of 10 mm) of less than 10% or even less than 5% does not prevent hardening of the light but appears to be opposite the addition of said oxidic fillers has a positive effect on the curing rate up to high layer thicknesses.

Component (d) (Catalyst)

The component (d), the hydrosilylation catalyst, preferably contains at least one metal selected from the group consisting of Pt, Pd, Rh, Ni, Ir or Ru, preferably Pt. The hydrosilylation catalyst can be used in metallic form, in the form of a complex compound and / or as a salt. The catalysts can be used with or without support materials in colloidal or powdered state. Examples of photoactivatable catalysts include diolefin-α-aryl-platinum complexes as disclosed in US 4,530,879, EP 122008, EP 146307 or US 2003-0199603, platinum diketonates such as (Pt (acac) ₂ ), as well as platinum compounds whose reactivity for example, with Azodicarbonsäureestem, as disclosed in US 4,640,939, controlled. Most preferred are transition metal compounds having at least one sigma-bonded alkyl or aryl radical, preferably corresponding platinum compounds, such as optional alkyl or - -

Trialkylsilyl-substituted cyclopentadienyl-tris-alkyl-platinum compounds, cyclopentadienyl-tris (triorganosilyl) -alkyl-platinum compounds, in particular alkylcyclopentadienyl-trimethyl-platinum, such as methylcyclopentadienyl-trimethyl-platinum. Particularly preferred catalysts, with regard to their reactivity and curing rate, are: C ⁵ -cyclopentadienyl) -trialkyl-piatin complex compounds with (Cp = cyclopentadienyl), such as (Cp) trimethylplatin and (methyl-Cp) trimethylplatinum. The amount of component (d) is preferably 0.1-5000 ppm, preferably 0.5-1000 ppm, more preferably 1-500 ppm, most preferably 2-100 ppm, calculated as metal, based on the weight of the components (a ) to (c) above.

Excipients

inhibitors

The rate of the hydrosilylation reaction is known to be influenced by a number of additional compounds, the so-called inhibitors (e). Thus, one can further influence on the rate of crosslinking after photoactivation, ie it determines, at a soft temperature and in which time the silicone composition or rubber mixture hardens or vulcanized after photoactivation to form an elastomeric molding. Expedient inhibitors for the photoactivatable hydrosilylation according to the invention at platinum concentrations above 30 ppm of platinum are inhibitors, such as vinylsiloxanes, 1,3-divinyltetramethyldisiloxane or tetravinyltetramethyltetracyclosiloxane. Other known inhibitors such as ethynylcyclohexanol, 3-methylbutynol or dimethyl maleate can also be used. The inhibitors serve to delay the crosslinking reaction in the desired manner after photoactivation. In principle, all inhibitors known for the class of the group of the platinum metals can be used, as long as a sufficiently long pot life is not already achieved by selecting the ligands of the catalyst (d). A preferred embodiment is to use the catalyst without the inhibitor. If the inhibitor component is used, preferably from about 0.001 to 0.5% by weight, particularly preferably from 0.05 to 0.2% by weight, in particular of the alkynols, of metal contents of component (d) of from 10 to 100 ppm are metered. The total amount of the possible auxiliary substances (e) is preferably 0 to 15 parts by weight based on 100 parts by weight of component (a) and (b). Photosensitizers can also be used as auxiliaries in order to increase the light yield in thin layers.

bonding agent

Suitable adhesion promoters include, for example:

(1): at least one organosiloxane having at least one alkoxysilyl group _»

(2): at least one organosilane having at least one alkoxysilyl group,

(3): at least one aromatic organic compound having at least two aromatic groups and at least one group reactive in the hydrosilylation reaction.

Adhesion Promoter Component (1) is preferably a polyorganosiloxane having at least one unit selected from the group consisting of:

RHS1O2 / 2 and

R ⁵ (R) SiO 2/2,

wherein R is as defined above and may be the same or different and R ^{5 is} selected from the group consisting of: unsaturated aliphatic groups having up to 14 carbon atoms, epoxy group-containing aliphatic groups having up to 14 carbon atoms, cyanurate-containing Groups and isocyanurate-containing groups,

and further comprising at least one unit of the following formula:

0 _2/2 (R) Si-R ⁴ -SiR _d (OR ³ ) _M (3) wherein

R is as defined above,

R ^{3 is} selected from H (hydrogen) and alkyl radicals having 1-6 carbon atoms,

R ^{4 is} a bifunctional optionally substituted hydrocarbon radical having up to 15 carbon atoms, which may have one or more heteroatoms selected from O, N and S atoms, and which is bonded to the silicon atoms through a Si-C bond, and wherein

d is 0 to 2. - -

Adhesion promoter component (2) is preferably selected from compounds of the formula:

X ^ CR ⁶ ₂ ) _e ^ (CH ₂ ) eSi _d (O ³ ) _3-d in which

X is selected from the group consisting of halogen, pseudohalogen, unsaturated aliphatic groups having up to 14 carbon atoms, aliphatic groups containing up to 14 carbon atoms containing epoxy groups, cyanurate-containing groups and isocyanurate-containing groups,

Y is selected from the group consisting of: single bond, heteroatom-containing group selected from: -COO-, -O-, -S- -CONH-, -HN-CO-NH-, R ^{6 is} selected from hydrogen and R which is defined as above

e is: 0, 1, 2, 3, 4, 5, 6, 7, or 8, and may be the same or different,

R is as defined above and may be the same or different,

R ³ is as defined above and may be the same or different,

d is 0, 1, or 2.

Preferred examples include:

Another group of the adhesion-promoting component (3) is preferably selected from compounds of the formula:

wherein

r is 0 or 1 _»

R ^{7 may be the} same or different and is selected from the group consisting of: hydrogen, hydroxy, halo, alkenyl, alkoxy, alkenyloxy, alkenylcarbonyloxy and aryl, and

a group of the formula: -ErSi (OR) 3-dRd _> wherein R is the same or different and d is as defined above,

a group of the formula -O-Si (R) 2R ¹ , wherein R and R ^{1 are} as defined above, a group of the formula: -Ef-Si (R) ₂ H, wherein R is as defined above,

wherein E is a divalent organic group having up to eight carbon atoms and 0 to 3 heteroatom groups selected from: -O-, -NH-, C = 0, and

-C (= 0) 0-, and

f is 0 or 1,

and Z is selected from the following groups:

-f ^CH } or wherein R ^{8 is} selected from the group consisting of: hydrogen atom, halogen atom or a substituted or unsubstituted alkyl group, aryl group, alkenyl group and alkynyl group, and

g is a positive number of at least 2,

wherein at least one of the groups selected from R ⁷ and R ⁸ is reactive in the hydrosilylation reaction.

A preferred component (3) includes: - -

wherein Z _r , R ⁷ , R ³ , R and d are each as defined above. A preferred light-curing silicone composition contains:

From 3 to 99% by weight of at least one alkenyl group-containing polysiloxane a),

0.2 to 60% by weight of at least one SiH-functional polysiloxane b),

From 0.1 to 80% by weight, more preferably from 5 to 50% by weight, of at least one filler c), preferably an oxidic filler, such as fumed silica,

at least one photoactivatable catalyst d), corresponding to a metal content of 1 to 500 ppm,

0 to 30% by weight of one or more auxiliary substances e),

in each case based on the total amount of components a) to c).

In a preferred embodiment, the silicone composition used according to the invention comprises:

a) 100 parts by weight of at least one alkenyl-containing polyorganosiloxane having a viscosity range of 0.025 and 500 Pa.s (25 ° C., shear rate gradient D of 1 s ^-1 ),

b) from 0.1 to 200 parts by weight of at least one polyorganohydrogen siloxane, wherein 0.5 to 20 mol, preferably 1 to 5 mol of the SiH groups are used per mol of the alkenyl groups,

c) optionally from 1 to 100 parts by weight of one or more fillers, d) from 0.5 to 1000 ppm of at least one hydrosilylation catalyst calculated as metal based on the amount of components (a) to (c), e) optionally from 0.0001 to 2% by weight of one or more inhibitors, based on the amount of components (a) to (c), and optionally further auxiliaries.

The application of the silicone rubber compositions used according to the invention is obtainable by mixing components (a) to (e), it being advantageous to combine the substances in preferred sequences and preferably to combine at least two partial mixtures immediately before activation. - -

In a preferred embodiment of the method according to the invention, after photoactivation, the silicone composition is curable within less than 6 minutes, preferably less than 5 minutes, more preferably less than 4 minutes. The photoactivation is carried out with light of a wavelength in the range of 200 to 500 nm (UV wavelength range). In the process according to the invention, for example, a UV radiation source from the group of UV lamps such as xenon lamps which can be operated as flashlamps is selected for the light activation, undoped or iron or gallium doped mercury lamps, blacklight and excimer lamps and LED UV lamps. The composite molded articles produced according to the invention preferably have an inner core of the selected thermoplastic resin with outer shell or molded elements of silicone elastomer. However, it is also possible by the process according to the invention to produce composite molded articles in which the thermoplastic resin is disposed on the outside and the silicone elastomer is located inside, as for example in damping elements in which, for example, a core of the silicone elastomer is in a thermoplastic pad. The latter embodiment is particularly accessible when the thermoplastic polymer / resin transmits the radiation necessary for curing the light-curing silicone composition.

In another preferred embodiment of the method, first of all a molded part is injected in step I) from a thermoplastic or thermoset-permeable thermoplastic largely permeable to UV light at 20-200 ° C. and a pressure of 1 to 400 bar. This molding thus obtained is at room temperature or above (20 to 200 ° C preferably 30-150 ° C) until the demolding of the finished part in step IV) of thermoplastic or thermoset and silicone fixed, optionally to a mold temperature below 200 ° C is cooled. In the subsequent step II), the light-curing silicone composition is sprayed under controlled pressure onto the side of the molded part of thermoplastic or thermosetting resin facing the mold cavity. The injection pressure for the light-curing silicone composition is 1-400 bar, preferably 1-200 bar, more preferably 1-30 bar. The melt temperature is preferably below the equilibrium melting temperature T _{m »} here the softening temperature (measured as Deflection temperature at 5 N) of the resin molding. The silicone composition is preferably at a temperature which is preferably 10 ° C, more preferably more than - -

20 ° C below the softening temperature of the resin molding, injected. Typically, step ii) is preferably carried out at temperatures of less than 90 ° C, more preferably less than 80 ° C (see Fig. 2).

In a further step III), the light-curing silicone composition is expediently irradiated by this molded part of thermoplastic or thermosetting resin with light of wavelength 190-600 nm and preferably with a specific power of 0.1-100 Watt / cm ² over appropriate 1- 500 seconds, preferably <200 seconds, in order to achieve the curing of the silicone composition. The irradiation preferably takes place with a specific irradiation energy of 1-50 J / cm ² at the temperatures mentioned.

The removal of the thermoplastic or thermosetting resin composite and cured silicone composition from the mold cavity is carried out in a next step IV), optionally with the aid of ejectors or compressed air.

Figure 2 shows schematically the method described above.

Step 1) shows the production of the thermoplastic or thermosetting molding. Steps II) and III) shows the irradiation of the silicone composition by the thermoplastic or thermosetting molding. Step i) and the subsequent steps may optionally be carried out in a molding tool using variable molding compounds.

The reference numerals are explained below:

1: UV-transparent plastic molded part,

2: mold for translucent molding,

3: LED UV light source,

4: UV-crosslinking silicone and

5: Mold for UV-curable silicone.

Figure 1 shows an example of a molded part produced according to the invention. The

Reference numerals mean:

6: cured silicone composition

7: molding of thermoplastic or thermosetting resin

8: breakthroughs for mechanical connection or anchoring

In the process according to the invention, the thermoplastic molding and the cured silicone composition may be cured by adhesive forces and / or by mechanical means. - ^"American forces or elements may be connected. That is, in principle, the bond between the thermoplastic molded part and the silicone elastomer molded part by adhesion or adhesion between the two mold parts and / or by mechanical connection of the two mold portions can be effected. In the latter case, by choosing a suitable geometry of the molded parts, in particular of the previously manufactured thermoplastic molded body portion, for example by recesses, such as in the form of threads, anchors, barbs, fasteners in the thermoplastic molding a firm connection to the silicone elastomer molded body portion generates (see Illustration 1 ). In the former case, various measures are suitable for promoting the adhesion between the thermoplastic molded body portion and the silicone elastomer molded body portion, which may be used alone or in combination. For example, the adhesion-promoting silicone composition described above can be added to the light-curing silicone composition used, or the surface of the thermoplastic molding fraction can be pretreated by suitable measures, such as etching, plasma treatment, flame treatment, coating by so-called primers. In one embodiment of the method according to the invention, the thermoplastic molding and the cured silicone composition are releasably bonded together. This is advantageous, for example, if the composite molded bodies produced according to the invention are to be recycled.

According to the method of the present invention, a variety of composite molded articles of thermoplastic molded article portion and silicone elastomer molded article portion can be easily produced in various fields of application. Examples of hard-soft molded parts made in accordance with the present invention include mechanical seals, automotive applications such as silicone lip fan dampers, pneumatic central locking pushbuttons, electrical items such as insulators, hollow tube insulators (silicon blades on PE or PP tubes) electronic keyboards, food packaging such as bottle caps or stoppers, such as wine bottle stoppers, champagne bottle stoppers, beer bottle stoppers, such as corks, coffee capsules, cap and dosing caps. Valves with elastic sealing lips, food containers or boxes (silicone gaskets in / on thermoplastic containers), kitchen utensils such as dough scrapers, diving masks, face masks, teething rings, pacifiers, thermoplastic soap dishes of acrylate or PVC with an elastomeric Base part made of light-curable silicone (see Fig. 2), ^" adult toys ^" such as vibrators, dildos, buttplugs and penis rings, furniture »shelves, haptic design objects with silicone elastomers, applications for textiles or shoes, brand emblems, sports and leisure items such as watch straps , Tools, tool handles, especially in the kitchen and medical technology, elastic slipping brakes or stacking aids in plates, bowls, syringe plugs, Intravenous valves, scrapers or spatulas, implants, hoses or valves, gegegbenfalls with integrated Flanschstücken, hoses with integrated bends, for example for household and medical technology.

There are several ways in which the composite molded articles according to the invention can be produced. A distinction is in particular those methods in which the thermoplastic molding is first produced in the mold, for example by injection molding, or the processes in which the preformed thermoplastic molding is placed in the mold, which is then filled with the light-curing silicone composition and finally with preferably UV Light is irradiated to form the composite moldings of the invention. In principle, the process of the invention is both continuous, for example in an extrusion process, as well as discontinuous feasible. In the former case, for example, a thermoplastic molding element, such as a hose, a strand or a pipe, continuously generated, which is passed after an equally continuous application of the silicone composition at an exposure station, and then, for example, wound and / or in suitable Sections is cut. Or the pre-fabricated thermoplastic or thermosetting molding, is discontinuously or continuously introduced into a mold, and after continuous application of the light-curing silicone composition, cured at an exposure station, and the resulting composite molding is continuously removed and worked up

More preferably, however, a particular mold or mold is loaded with either a preformed thermoplastic molding element into which the photohardening silicone composition is subsequently added and cured by UV radiation. Subsequently, the resulting composite body is removed, and the process is repeated (discontinuous mode of operation). Alternatively, the thermal - - Plastic mold element, for example, by injection molding in a common mold or mold previously generated.

The forms used in the process of the invention must of course have at least one radiation-transmissive, i. transparent region, which may consist of quartz glass or a plastic such as PMMA.

The composite moldings obtained by the process according to the invention may also be thick-walled composite body having - also in the region of the silicone elastomer - thicknesses of at least 3 mm, up to, for example, about 100 mm. More preferably, the composite molded bodies produced according to the invention have at least thicknesses of 3 mm and more, more preferably at least 10 mm to, for example, about 100 mm in all three dimensions. Accordingly, the composite shaped bodies according to the invention have dimensions which are suitable for accommodating at least one ball with a diameter of at least 3 mm, more preferably at least 10 mm, more preferably at least 20 mm. This also applies to the cured silicone portion which may also have such dimensions which are suitable for accommodating at least one ball with a diameter of at least 3 mm, more preferably at least 10 mm, even more preferably at least 20 mm.

The injection of the thermoplastic melts is expediently carried out at screw temperatures of 180-350 ° C. (LOPE-PA types or PEEK) and a pressure of 250-2500 bar in cavities or mold cavities which have a temperature of 15-160 ° C.

The plastic melt solidifies here with cooling in a few seconds per mm wall thickness and can then be removed from the mold and processed further.

The light-curable silicone liquid rubber (LSR) is expediently injected at 50-1000 bar and at a screw temperature of 20-35 ° C. (LSR) or 35-75 ° C. (highly viscous Si solid rubber), the cavity having a temperature of 15-100 bar. 80 ° C has.

As suitable irradiation times with UV light, it is expedient to choose times between 5 and 300 seconds with a surface-related power of 1-50 W.cm- ² and wavelengths of 190-400 nm.

The invention is illustrated by the following examples. Examples of materials

Materia! 1: PP Moplen HP400M, softening temperature 96 ° C (as Deflection Temp. At 5 N). Material 2: Light activatable silicone composition.

In a kneader 14.1 parts by weight of dimethylvinylsiloxy endstopptes polydimethylsiloxane (a1) having a viscosity of 10 Pa.s at 25 ° CM ^Vi 2D ₅₃₉ , 25.6 parts by weight of dimethylvinylsiloxy endstopptes polydimethylsiloxane (a1) with a Viscosity of 65 Pa.s at 25 ° C, 3.9 parts of hexamethyldisilazane, 0.03 parts by weight of 1, 3-divinyl-tetramethyldisilazane and 2.1 parts by weight of water mixed. Subsequently were

18 parts by weight of fumed silica (c) with a BET surface area of 300 m ² / g mixed, heated to about 100 ° C and stirred for about one hour and then at 150 ° C to 160 ° C of water and excess silazane - / Silanolresten removed by evaporation (finally vacuum at p = 20 mbar). It is then diluted with 33.4 parts by weight of a dimethylvinylsiloxy-terminated polydimethylsiloxane (a1) with a viscosity of 10 Pa.s.

10.4 parts by weight of a SiH crosslinker (component b)) consisting of a dimethylhydrogensiloxy end-stopped polydimethylhydrogenmethylsiloxane were added to 93.2 parts by weight of this mixture while stirring with a two-shaft kitchen mixer (Krups) at 25.degree and an SiH content of 2.3 mmol / g with a viscosity of 40 mPa.s at 25 ° C of the general formula M ₂ D ₁₀ ^H 2o oD.

Then, under yellow light (exclusion of light <550 nm), 2 parts by weight of the photoactivatable catalyst were stirred in over 5 minutes using a kitchen blender. This catalyst consisted of 2000 parts by weight of a linear vinylendgestoppten polydimethylsiloxane with the viscosity 10 Pa.s at 25 ° C with a vinyl content of 0.05 mmol / g and 1 part by weight of trimethyl (methylcyciopentadienyl) -platin (Fa. Strem) with a platinum content of 61, 1%. With this amount, one sets a platinum content of 6.4 ppm in the reactive mixture of the material 2. - -

Example 1 Preparation of a composite part of PP and silicone

In a two-component form, the to an injection molding machine Fa. Enge! Type LIM 200 is connected, one introduces polypropylene material 1 at a screw temperature of 200 ° C and a pressure of 1000 bar. The PP is injected into the mold, which had a temperature of 35 ° C and then cooled down in 60 seconds. The resulting molded part (Ausziehense) was set with a handling robot in the predetermined for the silicone elastomer cavity (mold cavity) and injected within 0.5 sec 4 g photocurable Silikonemisc ung the material 2 at 35 ° C at 100 bar. A UV lamp of the Phoseon type was irradiated through a 4 cm ² UV transparent polymethylacrylate (PM A) window into the cavity with the light-activatable silicone elastomer composition with UV light of wavelength 385 nm with a power of 4 W per area / cm ² for 15 sec at a distance of 1, 5 cm.

The PP molded part was here formed as a Auszießse with openings in einzubettenden part for injection molding with the silicone elastomer and its mechanical anchoring, as shown in Fig. 1.

After encapsulation and curing of the silicone elastomer was obtained a stopper for beverage bottles as shown schematically in Fig. 1, which could be removed from the mold.

Claims

1. A process for the production of plastic composite molded articles, which comprises the steps:

a) providing a molded part of thermoplastic or duromeric resin in a mold,

b) introducing a light-curing silicone composition into said

Mold containing said molding,

c) irradiating the photo-curable silicone composition with light of a wavelength suitable for curing the silicone composition to form a composite molded article of said molded article and the cured one

Silicone composition.

A process according to claim 1, wherein the molding used in step a) is a thermoplastic resin.

3. The method according to one or more of the preceding claims, wherein the thermoplastics after a heat distortion temperature (HDT) after

DIN EN ISO 75-1, -2 of less than 160 ° C.

4. The method according to one or more of the preceding claims, wherein the thermoplastic resins are selected from the group consisting of ABS, polyoxymethylene (POM); Polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyolefins selected from polyethylene (PE), polypropylene (PP) and polyethylene dicyclopentadiene polymers (COC), polymethyl methacrylate (PMMA), polyesters, polycarbonates (PC), polyvinyl chloride (PVC ), Polylactides (PLA), polystyrene (PS), celluloid, thermoplastic elastomers selected from ethylene-propylene-diene rubber or styrene / butadiene / styrene block copolymer (SBS) and styrene / ethene butene / styrene (SEBS) and polyurethanes ,

5. The method according to one or more of the preceding claims, wherein the thermoplastic resin is polypropylene.

The process of claim 1, wherein the thermosetting resins are selected from the group consisting of crosslinked epoxies, bakelites, crosslinked polyester resins, and crosslinked polyurethanes.

A method according to one or more of the preceding claims, wherein the light-curing silicone composition is selected from the group of hydrosilylation-curing silicone compositions.

A process according to one or more of the preceding claims, wherein the light-curing silicone composition is selected from the group of hydrosilylation-curing silicone compositions consisting of:

b) at least one polyorganosiloxane containing on average at least two SiH groups per molecule,

c) optionally one or more fillers,

d) at least one photoactivatable catalyst comprising a metal selected from the group consisting of Pt, Ru, Rh, Pd, Ir or Ni or a compound of said metal, and

e) optionally one or more auxiliaries.

A process according to one or more of the preceding claims, wherein the composite molded article is selected from the group consisting of hard-soft molded parts for mechanical engineering, automobile applications, electronic goods such as insulators, keyboards, food packaging such as bottle caps Coffee capsules, closure and Dosierkappen or. Valves, food containers, kitchen utensils such as dough scrapers, plates, bowls, diving masks, face masks, teething rings, baby suckers, vibrators, dildos, butt plugs, penis rings, furniture, shelves, haptic designed design objects with silicone elastomers, applications for textiles or footwear, brand emblems, sports and leisure Leisure articles such as watch straps, tools, tool handles syringe plungers, intravenous valves, scrapers or spatulas, implants, hoses or valves, if necessary, with integrated flange pieces, hoses with integrated elbows.

10. The method according to one or more of the preceding claims, wherein the thermoplastic or thermosetting molding and the cured silicone composition are connected by adhesive forces and / or by mechanical elements

11. The method according to one or more of the preceding claims, wherein the thermoplastic molding and the cured silicone composition are releasably connected together.

12. The method according to one or more of the preceding claims, wherein the thermoplastic or thermosetting molding is first produced in the mold.

13. The method according to one or more of the preceding claims, wherein the thermoplastic or thermosetting molding is already finished molded into the mold.

14. The method according to one or more of the preceding claims, which is carried out batchwise.

15. The method according to one or more of the preceding claims, wherein the shaped body has such dimensions, which are suitable to receive at least one ball with a diameter of at least 3 mm.

16. The method according to one or more of the preceding claims, wherein the cured silicone part has such dimensions, which are suitable to receive at least one ball with a diameter of at least 3 mm.

17. The method according to one or more of the preceding claims, characterized in that the light-curing silicone composition is irradiated by the thermoplastic or thermosetting molding.

18. A plastic-substance form obtained by a process according to one or more of the preceding claims.

19. Bottle caps and food containers according to a method according to one or more of the preceding claims.